A Study to Evaluate Tobevibart + Elebsiran in Chronic HDV Infection

April 7, 2026 updated by: Vir Biotechnology, Inc.

A Phase 3 Randomized, Open-Label Study to Evaluate the Efficacy and Safety of Tobevibart + Elebsiran Combination Therapy in Participants With Chronic HDV Infection (ECLIPSE 1)

This is a multicenter, open label, randomized Phase 3 clinical study to evaluate the efficacy and safety of the combination of tobevibart + elebsiran for the treatment of chronic hepatitis delta in comparison to delayed treatment.

Study Overview

Status

Active, not recruiting

Conditions

Intervention / Treatment

Study Type

Interventional

Enrollment (Actual)

124

Phase

  • Phase 3

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Canada
      • Montreal, Canada, H2X 1R9
        • Investigative Site
      • Ottawa, Canada, K1H8L6
        • Investigative Site
      • Québec, Canada, G1V 4G2
        • Investigative Site
      • Vancouver, Canada, V6Z 2C7
        • Investigative Site
    • Alberta
      • Calgary, Alberta, Canada, T2N 4Z6
        • Investigative Site
    • Quebec
      • Montreal, Quebec, Canada, H2L 4E9
        • Investigative Site
  • Georgia
      • Tbilisi, Georgia, 0102
        • Investigative Site
      • Tbilisi, Georgia, 0114
        • Investigative Site
      • Tbilisi, Georgia, 0159
        • Investigative Site
  • Germany
      • Frankfurt, Germany, 60590
        • Investigative Site
      • Hanover, Germany, 30625
        • Investigative Site
      • Heidelberg, Germany, 69120
        • Investigative Site
  • Moldova
      • Chisinau, Moldova, 2025
        • Investigative Site
  • New Zealand
      • Auckland, New Zealand, 1010
        • Investigative Site
  • Pakistan
      • Karachi, Pakistan, 74800
        • Investigative Site
      • Karachi, Pakistan, 75600
        • Investigative Site
      • Lahore, Pakistan, 54800
        • Investigative Site
      • Rawalpindi, Pakistan, 46000
        • Investigative Site
  • Romania
      • Bucharest, Romania, 021105
        • Investigative Site
      • Bucharest, Romania, 022328
        • Investigative Site
      • Bucharest, Romania, 030303
        • Investigative Site
  • Ukraine
      • Kyiv, Ukraine, 01135
        • Investigative Site
  • United Kingdom
      • London, United Kingdom, SE5 9RS
        • Investigative Site
      • London, United Kingdom, E1 1BB
        • Investigative Site
      • Manchester, United Kingdom, M8 5RB
        • Investigative Site
      • Nottingham, United Kingdom, NG7 2UH
        • Investigative Site
  • United States
    • Arizona
      • Chandler, Arizona, United States, 85224
        • Investigative Site
    • California
      • Los Angeles, California, United States, 90033
        • Investigative Site
      • Redwood City, California, United States, 94063
        • Investigative Site
      • San Francisco, California, United States, 94143
        • Investigative Site
    • Florida
      • DeLand, Florida, United States, 32720
        • Investigative Site
    • Illinois
      • Chicago, Illinois, United States, 60612
        • Investigative Site
    • Maryland
      • Baltimore, Maryland, United States, 21287
        • Investigative Site
    • New Jersey
      • Hillsborough, New Jersey, United States, 08844
        • Investigative Site
    • New York
      • New York, New York, United States, 10029
        • Investigative Site
      • New York, New York, United States, 10016
        • Investigative Site
      • New York, New York, United States, 10021
        • Investigative Site
    • Utah
      • Murray, Utah, United States, 84107
        • Investigative Site
    • Washington
      • Seattle, Washington, United States, 98105
        • Investigative Site

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  1. Male or female ages 18 to 70 years at screening
  2. Chronic HDV infection for >/= 6 months
  3. On NRTI therapy against HBV for at least 12 weeks prior to day 1 or have HBV DNA < 20 IU/ml at screening, currently on locally approved NRTI therapy
  4. Serum ALT > ULN and < 5x ULN
  5. Non-cirrhotic or Compensated Cirrhotic Liver Disease at screening

Exclusion Criteria:

  1. Any clinically significant chronic or acute medical or psychiatric condition that makes the participant unsuitable for participation.
  2. History of significant liver disease from non-HBV or non-HDV etiology
  3. History of allergic reactions, hypersensitivity, or intolerance to study drug, its metabolites, or excipients.
  4. History of anaphylaxis
  5. History of immune complex disease
  6. History of autoimmune disorder
  7. History or evidence of alcohol or drug abuse within 6 months before screening or a positive drug screen at screening unless it can be explained by a prescribed medication

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Arm 1 (Tobevibart + Elebsiran)
Participants will receive treatment with tobevibart + elebsiran for 240 weeks.
Drug: Tobevibart
Tobevibart administered by subcutaneous injection
Other Names:
  • VIR-3434
Drug: Elebsiran
Elebsiran administered by subcutaneous injection
Other Names:
  • VIR-2218
Experimental: Arm 2 (Tobevibart + Elebsiran)
Participants will receive tobevibart + elebsiran after an observational period for 240 weeks.
Drug: Tobevibart
Tobevibart administered by subcutaneous injection
Other Names:
  • VIR-3434
Drug: Elebsiran
Elebsiran administered by subcutaneous injection
Other Names:
  • VIR-2218

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Time Frame
HDV RNA < Lower Limit of Quantification (LLOQ), Target Not Detected (TND) and alanine aminotransferase (ALT) normalization (ALT </= Upper Limit of Normal [ULN]) at Week 48 for Arm 1 vs at Week 12 for Arm 2
Time Frame: Up to 48 weeks
Up to 48 weeks
Incidence of Treatment-emergent adverse events (TEAEs) and serious adverse events (SAEs) through Week 12
Time Frame: Up to 12 weeks
Up to 12 weeks

Secondary Outcome Measures

Outcome Measure
Time Frame
HDV RNA < LLOQ, TND at Week 48 for Arm 1 vs Week 12 for Arm 2
Time Frame: Up to 48 weeks
Up to 48 weeks

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Vir Biotechnology, Inc.

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

March 12, 2025

Primary Completion (Estimated)

December 31, 2026

Study Completion (Estimated)

May 1, 2031

Study Registration Dates

First Submitted

March 24, 2025

First Submitted That Met QC Criteria

March 24, 2025

First Posted (Actual)

March 30, 2025

Study Record Updates

Last Update Posted (Actual)

April 8, 2026

Last Update Submitted That Met QC Criteria

April 7, 2026

Last Verified

April 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • VIR-CHDV-V203

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

Yes

Studies a U.S. FDA-regulated device product

No

product manufactured in and exported from the U.S.

Yes

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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